Yet, even from Pliny’s _Panegyric_, we can see that the recognition of the prerogatives, or rather of the dignity, of the Senate, the coexistence of old republican forms side by side with imperial power, depended entirely on the grace and tolerance of the master of the legions. Nothing could be more curious than Pliny’s assertion of the senatorial claims, combined with the most effusive gratitude to Trajan for conceding them. The emperor is only _primus inter pares_, and yet Pliny, by the whole tone of his speech, admits that he is the master who may equally indulge the constitutional claims or superstitions of his subjects or trample on them. In the first century a power, the extent of which depended only on the will of the prince, and yet seemed limited by shadowy claims of ancient tradition, was liable to be distrustful of itself and to be challenged by pretenders. In actual fact, the prince was so powerful that he might easily pass into a despot; in theory he was only the first of Roman nobles, who might easily have rivals among his own class. Pliny congratulates Trajan on having, by his mildness and justice, escaped the terror of pretenders which haunted the earlier emperors, and was often justified and cruelly avenged.(256) In spite of the lavish splendour of Nero or Caligula, the imperial household, till Hadrian’s reorganisation, was still modelled on the lines of other great aristocratic houses. Nero’s suspicions were more than once excited by the scale of establishments like that of the Silani, by wealth and display like Seneca’s, by the lustre of great historic traditions in a gens like the Calpurnian.(257) The loyalty of Corbulo could not save him from the jealousy aroused by his exploits in eastern war.(258) And the power of great provincial governors, in command of great armies, and administering realms such as Gaul or Spain or Syria, was not an altogether imaginary danger. If Domitian seemed distrustful of Agricola in Britain, we must remember that he had in his youth seen Galba and Vindex marching on Rome, and his father concentrating the forces of the East for the overthrow of Vitellius in the great struggle on the Po.